More on the comments above, and then I'll let this run its course regardless of what direction is goes.

Let's take a real-world example from my latest build on the predictive power of a DCR value:
1. I've profiled my cam lobe curve and know that the SAE seat duration (measured at .004" lobe lift above lash) for my solid roller is 307* with .018" lash.
2. Using Wallace Racing's camshaft event calculator, I've determined that the SAE IVC is 77.5* ABDC
3. Using Wallace Racing's dynamic compression calculator, I've determined that with my static compression ratio of 11.47:1, the dynamic compression ratio is 8.06:1. It also "thinks" my dynamic cranking pressure is 161.44 PSI.
4. According to DV's DC/Octane chart, I can run 91 octane R+M/2 fuel at 170* F water temp (even though my car runs a 160* 'stat).

Observations:
A. My engine's cranking pressure is more like 190+
B. When we dyno'd the engine using 3500-72000 RPM pulls, there's no doubt in my mind it would have gone into "death rattle" at some point using 91 octane, regardless of .040" quench, aluminum heads & heart-shaped chambers
C. Anyone who wants to build an identical engine to prove me wrong is welcome to


So... let's "game" the calculator input and use the IVC @ .020" of 74* ABDC, despite that fact that we've now lost all the effect of lash on actual duration:
- "Your dynamic compression ratio is 8.37:1"
- "Your dynamic cranking pressure is 169.53 PSI"

According to DV's DC/Octane chart, I can run 92 or 93 octane R+M/2 fuel. And the 170 PSI calc'd cranking pressure is still waaaay below reality.


So... let's totally "crutch" the calculator input and use the IVC @ .050" of 57* ABDC, despite that fact that we've now lost all the effect of lash on actual duration AND have completely ignored the fact that the duration at .050" value can't be used accurately to extrapolate an IVC point due to the wide variety of cam profiles available with approx. the same .050" duration.
- "Your dynamic compression ratio is 9.60:1"
- "Your dynamic cranking pressure is 202.18 PSI"

According to DV's DC/Octane chart, I need to run 98 or 99 octane R+M/2 fuel.


Perhaps the last attempt is the most accurate at predicting cranking pressure and octane requirement... but it also required pulling 20* out of the MEASURED SAE IVC point, which is what the engine is actually going to "see" when running.

Familiar with the term GIGO? Garbage In, Garbage Out... If you have to f**k with the actual data that much to make your tool's results come out within reason, "something" is flawed.